The Endocytic Uptake Pathways of Targeted Toxins Are Influenced by Synergistically Acting Gypsophila Saponins
| Autor: | Matthias F. Melzig, Christopher Bachran, Alexander Weng, Stefanie Schneider, Hendrik Fuchs, Diana Bachran |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Gypsophila
Saporin Endosome Blotting Western Endocytic cycle Pharmaceutical Science Caryophyllaceae medicine.disease_cause Models Biological Downregulation and upregulation Epidermal growth factor Cell Line Tumor Drug Discovery medicine Humans Receptor integumentary system biology Toxin Immunotoxins Drug Synergism Saponins Flow Cytometry biology.organism_classification Endocytosis Cell biology Biochemistry biology.protein Molecular Medicine hormones hormone substitutes and hormone antagonists HeLa Cells Signal Transduction |
| Zdroj: | Molecular Pharmaceutics. 8:2262-2272 |
| ISSN: | 1543-8392 1543-8384 |
| Popis: | The expression of the epidermal growth factor (EGF) receptor is upregulated in many human tumors. We developed the targeted toxin SE, consisting of the plant toxin saporin-3 and human EGF. The cytotoxic effect of SE drastically increases in a synergistic manner by a combined treatment with Saponinum album (Spn), a saponin composite from Gypsophila paniculata L. Here we analyzed which endocytic pathways are involved in the uptake of SE and which are mandatory for the Spn-mediated enhancement. We treated HER14 cells (NIH-3T3 cells transfected with human EGF receptor) with either chlorpromazine, dynasore, latrunculin A, chloroquine, bafilomycin A1 or filipin and analyzed the effect on the cytotoxicity of SE alone or in combination with Spn. We demonstrated that SE in combination with Spn enters cells via clathrin- and actin-dependent pathways and the acidification of the endosomes after endocytosis is relevant for the cytotoxicity of SE. Notably, our data suggest that SE without Spn follows a different endocytic uptake pathway. SE cytotoxicity is independent of blocking of clathrin or actin, and the decrease in endosomal pH is irrelevant for SE cytotoxicity. Furthermore, Spn has no influence on the retrograde transport. This work is important for the better understanding of the underlying mechanism of Spn-enhanced cytotoxicity and helps to describe the role of Spn better. |
| Databáze: | OpenAIRE |
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